Mutants of Arabidopsis lacking starch branching enzyme II substitute plastidial starch synthesis by cytoplasmic maltose accumulation

Three genes, BE1, BE2, and BE3, which potentially encode isoforms of starch branching enzymes, have been found in the genome of Arabidopsis thaliana. Although no impact on starch structure was observed in null be1 mutants, modifications in amylopectin structure analogous to those of other branching enzyme II mutants were detected in be2 and be3. No impact on starch content was found in any of the single mutant lines. Moreover, three double mutant combinations were produced (be1 be2, be1 be3, and be2 be3), and the impact of the mutations on starch content and structure was analyzed. Our results suggest that BE1 has no apparent function for the synthesis of starch in the leaves, as both be1 be2 and be1 be3 double mutants display the same phenotype as be2 and be3 separately. However, starch synthesis was abolished in be2 be3, while high levels of alpha-maltose were assayed in the cytosol. This result indicates that the functions of both BE2 and BE3, which belong to class II starch branching enzymes, are largely redundant in Arabidopsis. Moreover, we demonstrate that maltose accumulation depends on the presence of an active ADP-glucose pyrophosphorylase and that the cytosolic transglucosidase DISPROPORTIONATING ENZYME2, required for maltose metabolization, is specific for beta-maltose.     

The Gene Construction Kit: a new computer program for manipulating and presenting DNA constructs

The Gene Construction Kit is a new tool for manipulating and displaying DNA sequence information. Constructs can be displayed either graphically or as formatted sequence. Segments of DNA can be cut out with restriction enzymes and pasted into other sites. The program keeps track of staggered ends and notifies the user of incompatibilities and offers a choice of ligation options. Each segment of a construct can have its own defined thickness, pattern, direction and color. The sequence listing can be displayed in any font and style in user defined grouping. Nucleotide positions can be displayed as can restriction sites and protein sequences. The DNA can be displayed as either single- or double-stranded. Restriction sites can be readily marked. Alternative views of the DNA can be maintained and the history of the construct automatically stored. Gel electrophoresis patterns can be generated and can be used in cloning project design. Extensive comments can be stored with the construct and can be searched rapidly for key words. High quality illustrations showing multiple editable constructs with added graphics and text information can be generated for slides, posters or publication.     

SURGICAL EMERGENCIES

Action according to preconceived plans may be life-saving at the scene of accidents involving serious injury to several persons. Severe hemorrhage and respiratory obstruction must be dealt with immediately. As the latter may not be apparent at a glance, it should be looked for specifically. Artificial respiration may be necessary. Spinal puncture is a procedure in first aid which should be carried out at the site of an accident if there are symptoms of cerebral edema or of increased cerebral pressure.Routine plans should be laid to meet the emergency of cardiac arrest on the operating table. The surgeon must be prepared to begin cardiac massage within three minutes in such instances.     

SURGICAL EMERGENCIES

Action according to preconceived plans may be life-saving at the scene of accidents involving serious injury to several persons. Severe hemorrhage and respiratory obstruction must be dealt with immediately. As the latter may not be apparent at a glance, it should be looked for specifically. Artificial respiration may be necessary. Spinal puncture is a procedure in first aid which should be carried out at the site of an accident if there are symptoms of cerebral edema or of increased cerebral pressure.Routine plans should be laid to meet the emergency of cardiac arrest on the operating table. The surgeon must be prepared to begin cardiac massage within three minutes in such instances.     

Modification of commerical and custom-built slab gel electrophoresis units for two-dimensional polyacrylamide gel electrophoresis

Many commercial and custom-built slab gel electrophoresis units can be modified to function as two-dimensional polyacrylamide gel electrophoresis units with the insertion of Plexiglas adapters. These adapters can be made for about $50 a pair and can be used for either temporary or permanent modification of the slab gel units. The physical dimensions of the adapters can be varied to permit great flexibility in the diameter of cylinder gels and the thickness of slab gels that can be run together. For example, proteins from 6-mm cylinder gels can be easily separated on 1-mm slab gels, which can then be dried for autoradiography.     

从医院等级评审谈医院伦理委员会建设

通过对照医院等级评审标准,阐述了评审标准对医院医学伦理学建设的相关要求,分析了医院伦理委员会建设中存在的问题,提出了推进医学伦理建设的建议。文章强调,推进伦理学教育,加强医德医风建设;严格伦理学督导,提高医疗科研水平;遵循伦理学原则,构建和谐的医患关系。     

Setting Up International (Adversary) Regimes in the South China Sea: Analyzing the Obstacles from a Chinese Perspective

If the sovereignty issue can be shelved, solved, or resolved, the six claimant states of the South China Sea will have to establish a series of international regimes. The following questions need to be answered: Do all the claimants understand the concept of international regimes? Would the regimes be imposed? Would there be hegemon(s) in the South China Sea? If so, which country or multiple entities will be involved? What would be the outcome of having international regimes in the South China Sea? Can the experience elsewhere be applied to the South China Sea?     

“食品微生物学”微课的开发设计与制作

微课作为一种以学习者为中心设计的可视化学习资源,因其短小精悍的特点已逐渐受到移动学习者的欢迎。本文介绍"食品微生物学"微课设计开发与制作方面的心得与体会。首先应有独具匠心的教学设计,在此基础上再采用有效的微课制作方式。教学设计时应精心选题,力求快速有效切题,线索清晰,亮点突出,收尾干净利落,还应树立危机意识。微课制作时要根据主题选择合适的微课表现形式,制作有视觉美感的PPT,录制清晰稳定的图像,最后剪辑、美化、合成得到微课视频。     

制备型高效液相色谱法分离蛋白质的研究

生物工程的发展,特别是生化制品下游处理技术的兴起,对现代分离科学提出了更高的要求,研究和开发各类生化物质特别是活性生物大分子的分离纯化技术,已成为一项十分重要的研究课题。在现有的分离技术中,液相色谱,尤其是80年代在分析型高效液相色谱(HPLC)基础上兴起的制备型HPLC,在大规模分离纯化生物活性物质特别是蛋白质方面已显示出巨大的应用潜力,引起了各国研究者的高度重视^[1-5].本文利用自行设计的制备型HPLC分离装置,对牛血清白蛋白(BAS)和牛血清红蛋白(HG)的制备分离过程进行了实验研究,着重考虑了流动流速、柱超载方式、柱长等因素对BAS和HG分离度的影响。     

Ethical and regulatory issues arising from proteomic research and technology

Over the last two decades, medical research has begun to make extensive use of products of human origin in therapeutics, oncology, and most recently, in genetic diseases. This has raised many ethical issues involving patient rights, including issues of consent. Besides informed consent, researchers should address several topics when designing studies using human tissues. Reward for the patient should be kept minimal. Sample transfer should be organized along non-profit lines, at least in Europe. Sampling procedures should be at no risk for human volunteers, and at minimal risk for patients. Biosafety aspects should be addressed, in particular when international collaborations are intended or when collaboration is existing between academia and industry. Regulations on importation and exportation of human tissues should be observed. Data acquisition and storage should be addressed in accordance with national data protection regulations, in particular when using computerized databases. If follow-up information is to be taken, the authorization for such information should be requested. The right for patient's information (or for no information) on the research results should also be addressed. The issues of validation and patenting should be also solved, usually by informing the patient that he/she will have no commercial rights on potential research results. The patient should be told if the samples are transferred to another research laboratory or private company. Samples and related data should be destroyed on request at any time point during the course of the study. If possible, traceability of the donor should be ensured.     

INTESTINAL OBSTRUCTION COMPLICATING ACUTE PERFORATIVE APPENDICITIS

Upon preoperative diagnosis of acute small bowel obstruction, without an obvious cause, acute perforative appendicitis must be considered. Reevaluation of the history and careful reexamination of the physical findings with that diagnosis in mind should be carried out. If appendiceal disease is likely, maximum antibiotic therapy must be begun immediately along with the administration of fluids, electrolytes and other corrective therapy. A mercury-weighted small bowel tube should be inserted and every effort made to advance it into the small bowel before operation. Operative treatment should be restricted to the least possible. A McBurney incision is best unless wider operation is indicated. If an abscess is present, drainage alone may be the procedure of choice. Severely distended and decompensated small bowel must be decompressed, for if not relieved it can be the cause of death in acute perforative appendicitis. Decompression may be accomplished either by small bowel intubation with continuous suction or by enterotomy and aspiration. If not relieved, small bowel distention will be the mechanism responsible for death in a large percentage of patients with acute perforative appendicitis.     

Alternative hypotheses for the effects of drugs in small-scale clinical studies

New drugs that will be investigated in the future are expected to deal with chronic diseases, where the number of patients available for controlled clinical trials will be small and where the long-term sequelae that it is hoped will be ameliorated take a long time to occur. Thus, it would be useful to construct powerful tests of hypotheses that can be used to compare subtle intermediate measures of change in condition. This paper examines the probabilistic characteristics of these measures and the changes in them that might be expected from drug therapy.     

黑河流域生态经济带分异协调规律与耦合发展模式

在西北干旱地区建设黑河流域生态经济带,是从根本上高效配置流域水资源,彻底化解流域上,下游利益冲突,实现利益共享,保护流域生态环境,推进流域可持续发展,全面实施国务院黑河流域分水方案的重要途径,通过对黑河流域生态经济带上－中－下游投入产出效益的比较分析和流域上、中、下游生态－生产、生活系统发展分异及互动协调关系的分析,提出了黑河流域生态经济带上－中－下游多维互动的协调耦合发展模式,进而提出了黑河流域生态经济带建设与发展的主要途径,包括推进黑河流域经济发展一体化和集成管理公司化,大力推行全流域水资源的差异化有偿使用制度,实施流动上、中、下游的水权转让贸易,实行规范的流域财政转移支付制度,建立流域资源与生态环境和经济的整合帐户体系,实行跨行政区域河流边界水量水质达标交接制度,等等。     

Shave excision of superficial solar skin lesions

Shave excision is a useful technique for the treatment of superficial solar lesions. The most common of these is the solar keratosis, which can be a red or gray scaling lesion. This can at times be difficult to differentiate from the superficial basal cell carcinoma or squamous cell carcinoma or their more infiltrating types. Shave excision gives the advantage of a histopathologic report. Lesions found to be infiltrating or in danger of recurrence can then be further excised. The cosmetic appearance of the healed shave excision site is generally quite good, although it can be paler than the surrounding skin. If this is likely to be a problem, the shave graft can be applied, as with deeper shave excisions. A thin shave graft also can be used to repigment pale scarred areas. A series of 1313 shave excised lesions is analyzed.     

CURRENT NOTES AND NOTICES

These are collated by Gwen Bonham, the Union's Administrative Secretary. Requests for the publication of information or other required assistance will be sympathetically considered. Publicity will gladly be given to relevant grants and awards that can be applied for, and to new societies which might be of interest to our readers. Details of conferences and meetings will also be included if sent to the Administrative Secretary at least 6 months in advance of the event. All items for Current Notes and Notices should be sent to the BOU, % The Natural History Museum, Tring, Hertfordshire HP23 6AP, UK .     

Interactive robots in experimental biology

Interactive robots have the potential to revolutionise the study of social behaviour because they provide several methodological advances. In interactions with live animals, the behaviour of robots can be standardised, morphology and behaviour can be decoupled (so that different morphologies and behavioural strategies can be combined), behaviour can be manipulated in complex interaction sequences and models of behaviour can be embodied by the robot and thereby be tested. Furthermore, robots can be used as demonstrators in experiments on social learning. As we discuss here, the opportunities that robots create for new experimental approaches have far-reaching consequences for research in fields such as mate choice, cooperation, social learning, personality studies and collective behaviour.     

Assessment of the potential germ cell mutagenicity of industrial and plant protection chemicals as part of an integrated study of genotoxicity in vitro and in vivo

An approach is described that enables the germ cell mutagenicity of chemicals to be assessed as part of an integrated assessment of genotoxic potential. It is recommended, first, that the genotoxicity of a chemical be defined by appropriate studies in vitro. This should involve use of the Salmonella mutation assay and an assay for the induction of chromosomal aberrations, but supplementary assays may be indicated in specific instances. If negative results are obtained from these 2 tests there is no need for the conduct of additional tests. Agents considered to be genotoxic in vitro should then be assessed for genotoxicity to rodents. This will usually involve the conduct of a bone marrow cytogenetic assay, and in the case of negative results, a genotoxicity test in an independent tissue. Agents found to be non-genotoxic in vivo are regarded as having no potential for germ cell mutagenicity. Agents found to be genotoxic in vivo may either be assumed to have potential as germ cell mutagens, or their status in this respect may be defined by appropriate germ cell mutagenicity studies. The basis of the approach, which is supported by the available experimental data, is that germ cell mutagens will be evident as somatic cell genotoxins in vivo, and that these will be detected as genotoxins in vitro given appropriate experimentation. The conduct of appropriate and adequate studies is suggested to be of more value than the conduct of a rigid set of prescribed tests.     

Accuracy and precision in sediment chronology

Several complications are encountered in radiocarbon dating of limnological samples. The contamination problem is obvious. Since lake sediments are usually composed of both allochthonous and autochthonous material the origin must be considered. The organic content may give some guidance. Graphite in the catchment area and a low organic content indicate a potential risk of major errors in the dates. Organic material from the surroundings may be displaced into a lake by creeks, snowslides and wind. Such material may be older than, or contemporaneous with the sediment deposited at the same time. Water-level changes and wave action may cause erosion and thus admixture of old material. Such contamination can sometimes be traced via different fractions extracted mechanically or chemically. The accelerator technique has made it possible to date small samples and thus macrofossils can be selected as the material to be used for dating far more frequently than is possible with the conventional technique for activity measurement.Another problem is the reservoir effect — thus the lower ¹⁴C activity of the dissolved bicarbonate and carbon dioxide than of the atmosphere. There may be several reasons besides dissolved carbonates in hard-water lakes. Some plants even use carbon dioxide in the sediment. It is thus to be expected that submerged plants will be dated too old. Selection of plant remains for dating is thus no guarantee of an accurate date. The material to be preferred is terrestrial, such as tree leaves or remains of emergent plants.Bioturbation must not be forgotten since this means that old material may be found too high in a sediment, and young material can be brought downwards in the sediment. A single date may be very misleading. Under rather stable conditions the sediment accumulation rate can be roughly estimated and acceptable dates obtained despite the complications.It may be worth sieving gyttja samples to remove roots and rootlets. Roots in peat should also be removed. Diagrams are available of the errors due to certain degrees of contamination by younger or older material.The ¹³C content must be measured to allow a normalisation. The present knowledge of the secular variations of the ¹⁴C activity allows calibration of dates made on wood etc. The same curves cannot be used for submerged material because of the lower ¹⁴C activity. Sudden changes of the atmospheric ¹⁴C activity are smoothed. Certain age ranges give better resolution than others. Recent curves indicate that strange results are to be expected for Holecene samples with a real age of 7000 years or older. Finally bacterial influence during storage may influence the isotopic composition.     

Binary Longitudinal Data Analysis with Correlation a Function of Explanatory Variables

When binary responses are observed over time, the dependence between observations for an individual must be considered. If the focus of a study is to identify the relationship between the binary response and a set of explanatory variables then the dependence between observations may also depend on the explanatory variables. An extension of a model where dependence is assumed to be constant will be considered. A model previously proposed for dependent binary responses will be revisited and a robust estimate of the variance-covariance matrix of coefficient estimates will be suggested to provide estimates of standard errors. The results of simulation studies investigating the properties of coefficient estimates will be discussed. An example based on a study of the AIDS epidemic and intravenous drug use behaviour will be analyzed to illustrate the techniques.     

Phylogeny of the fish leeches (Oligochaeta, Hirudinida, Piscicolidae) based on nuclear and mitochondrial genes and morphology

The phylogeny of the Piscicolidae was analysed from combined 18S rDNA, cytochrome c oxidase subunit I (CO-I), nicotinamide adenine dinucleotide dehydrogenase subunit I (ND-I) and morphological data using parsimony. A worldwide distribution of Piscicolidae was represented for the first time. While the family Piscicolidae was supported as a monophyletic group, the traditional subfamilies based on morphology were not supported. The Platybdellinae was polyphyletic and formed four distinct clades, and Bathybdella sawyeri did not group with any other platybdellins. The Piscicolinae was also polyphyletic, also forming four distinct clades. The pontobdellin genus Stibarobdella was shown to be the basal taxon within the Piscicolidae; however, the Pontobdellinae was found to be paraphyletic if Oxytonostoma was included. The genera Aestabdella , Austrobdella, and Malmiana were found to be paraphyletic; the genera Calliobdella, Cystobranchus, and Platybdella were found to be polyphyletic. The species Myzobdella lugubris was not found to be monophyletic. It is proposed that Oxytonostoma be transferred out of the Pontobdellinae, that Aestabdella be synonymized with Pterobdella , that Calliobdella vivida be returned to Cystobranchus , that Gonimosobdella be synonymized with Cystobranchus , and that Piscicolaria be synonymized with Myzobdella . The synonymy of Malmiana and Heptacyclus is confirmed, with Heptacyclus having priority. Piscicola milneri is confirmed to be a separate species from Piscicola geometra .